In the field of rotating machinery, and in particular propulsion equipment, it is a common occurrence to couple together two shafts which may have a common axis of rotation or which may even be perpendicular with respect to one another. The "coupling" often requires that a lubricant be introduced into the coupling area and that the coupling guard seal assembly be constructed so as to contain the lubricant without leakage. The coupling guard seal assembly may include two coaxial cylinders having their remote ends attached to separate machine casings and their proximate ends jointed to each other in overlapping relation. It is further common to provide an annular seal between the overlapping surfaces to prevent axial leakage of fluid out of the coupling guard seal assembly. The present invention addresses the seal between the overlapping cylinders.
A coupling guard seal assembly is carefully assembled with a seal interposed between overlapping surfaces. Misalignment of that seal during assembly or movement of the seal during subsequent use can only be corrected by total disassembly of the coupling guard seal assembly and subsequent reconstruction.
Also, in the assembly of a coupling guard, it is desirable for the overlapping ends of the cylinders to fit as tightly together as possible. The annular seal increases the requirement for annular radial clearance which is inconsistent with the aforesaid desirability of a tight almost interference fit between the cylinders.